Disease associated balanced chromosome rearrangements-report on 12 cases

ABSTRACT

The population frequency of familial disease balanced chromosome rearrangement with discordance for an abnormal phenotype is unknown. De novo balanced chromosome rearrangements are present in approximately 12000 newborn. The increased frequency of associated diseases may be due to truncation, inactivation or overexpression of specific genes. Uniparental disomy [UPD] has also been implicated. We report on 12 cases with apparently balanced chromosome rearrangements with abnormal phenotypes, 8 familial [5 families] and 4 de novo. Maternal inheritance accounted for 7/8 cases. The rearrangements included reciprocal translations in 8 cases, Robertsonian translocation in 2 cases and pericentric inversion in 2 cases. Apparently balanced rearrangements in general, represent an interpretational and counseling dilemma when detected in cases with abnormal phenotypes and/or mental retardation